Mirrored VR Window doesn't want to Maximize neither go fullscreen

hi,

sorry for my impatience.

But I find another way tomaximize monitor resolution display in vive vr mode. I have tried it,. It works well.

https://forums.unrealengine.com/showthread.php?117032-Problem-about-monitor-resolution-display-in-vive-vr-mode&p=567157&viewfull=1#post567157